热轧工艺对MGH754合金板材组织及性能的影响

通过组织分析和断口分析等方法,研究了轧制方向对MGH754合金板材组织和高温强度的影响。结果表明：由于发生了相对完全的二次再结晶,横向轧制板材能得到理想的终态组织。同时,横向板材的高温强度特别是持久强度要优于纵向轧制板材。合理分配储存能,从而最终发生完全的二次再结晶,获得盘状粗晶组织是MGH754合金板材获得优异高温强度的前提。     

A computational algorithm based on biogeography-based optimization method for computing power system security constrains with multi FACTS devices

A major role is played by the analysis of power system security in heightening system security and in system collapse condition avoidance. This article presents a cutting edge mechanism which is devised applying transmission line loadings as well as variance in bus voltage magnitude. The use of flexible alternating current transmission systems devices improves the objectives of generation fuel charges in addition to the severity index proposed which were investigated considering the contingency circumstances of generator(s) or/and transmission channel(s). To boost system security in spite of contingency circumstances in the existence of unified power flow controller or UPFC, it would be most appropriate to pinpoint a most advantageous position to install aforementioned device. We propose a model of UPFC where power insertion is done by using voltage source. Also a procedure to incorporate the same and a strategy to find optimum position has been proposed which uses line overload sensitivity indices. This work mainly focused on establishment of available transfer capability on the heavily congested line. The proposed congestion management scheme alleviates the heavy stress in transmission line and provides an ample corridor for the power to flow. Biogeography-based optimization or BBO in short, is a technique which is a growing recognized optimization method which has been lucratively engaged in solving intricate optimization problem in dissimilar fields. The BBO provides better results than the metaheuristic counter parts such as Genetic Algorithm and Particle Swarm Optimization. The effectiveness of proposed BBO has been tested on standard IEEE 30 bus system and the results are compared with classic methods and other metaheuristic methods. This is established through the MATLAB package. Improved bus voltage profile was also attained and it can be inferred from the outcome that the prospective approach can drastically enhance security of power system when comparing with other optimization methods.     

IEEE-1394b光总线扩展技术研究

本文提出一种基于IEEE-1394b协议的光总线系统实现方案。并以DSP和IEEE1394b协议芯片为基础,利用CPLD进行时序配合,完成了光总线系统总线扩展电路的硬件电路和程序设计,使光总线系统可以兼容采用多种通用通信协议的设备。在基于总线扩展电路搭建的光总线系统中,从PC端的总线系统网络拓扑图可以看出所设计的总线扩展电路可以满足应用的需求。     

基于HP54504A的物理模型参数测量系统的研制与开发

介绍了一种物理模型参数测量系统。系统由HP-54504A示波器、微机、IEEE-488接口卡、同步触发器、超声发射源和放大器组成。系统有外同步和内同步两种工作方式。使用OMT方法设计该系统，面对对象设计软件。系统在PC机Windows98环境下运行。介绍了系统的功能及进行物理模型参数测量的开发实例。该系统的开发为HP-54504A用户提供了方便。     

量热计数据采集和处理系统的设计

本文建立了以ＰＣ２８６微机为核心的量热计数采集和处理系统，给出了修正量热计热损失的计算公式，改变了传统的量热计测量方法。     

MGH754合金挤压棒材的二次再结晶与织构

研究了ＭＧＨ７５４合金在二次再结晶过程中的组织和结构变化。结果表明，合金大热挤压状态具有细小的等轴晶组织，织构微弱，有利于进行殂变加工；二次再结晶后，组织为粗大的柱状晶，且出现强烈的织构；随着退火时间延长，「１１０」〈００１》和「１００」〈００１〉织构含量明显增加，而「１１０」〈１１１〉，「１１０」〈１１３〉和「１１２」〈１１１〉等织构的含量减少，合金棒材的纵向主要为〈００１〉取向。     

火线（IEEE—1394）用于虚拟仪器的研究

虚拟仪器发展中提出了三项基本要求：开放式工业标准性、互换性和互操作性。文中从这三项要求出发，指出了虚拟仪器发展中的问题，提出了将计算机外设广泛应用的火线（ＩＥＥＥ１３９４）用于虚拟仪器的方案，介绍了火线的技术特点，探讨了火和于虚拟仪器的前景、形式和要做的工作。